Battery charging systems are not new. They are used to recharge batteries in many products used today including an automobile, a cordless telephone or cell phone, flashlights, calculators, portable computers, portable stereos, and may be used to directly recharge batteries themselves. Most of these charging systems require some sort of wire connection or physical contact with electrodes in order to recharge a battery.
Inductive or electromagnetic charging systems were introduced in order to charge systems without requiring a physical electrical connection. These were introduced for example in charging a battery in an electric tooth brush or batteries in electric automobiles. These electromagnetic charging systems eliminated the use of physical contacts or electrodes. This avoided the wear on physical contacts or electrodes normally associated with the numerous times a device would be recharged. Additionally the systems were more user friendly in that the devices were easier to recharge. The charging system for an automobile or tooth brush is an inductive or electromagnetic charging system having coils to transmit an electromagnetic field from the battery charger and receive the electromagnetic field in order to generate current within the device being charged. Coils for transmitting and receiving a charge tend to be large and cumbersome making it very difficult to integrate the charging components into a very small area. Previously space was not a large problem because previous battery charged devices, such as the tooth brush and automobile, have sufficient space for the relatively large charging components. Additionally, prior battery charged devices have required large capacity storage and efficient battery charging systems and often times included a magnetic core to increase charging efficiency. A magnetic core added to an inductive charging systems makes it more difficult to integrate a charging system into a very small area.
Today there are systems where it is desirable to manufacture rechargeable active devices at high volumes and low costs thereby increasing the utility and avoiding the early disposal of low cost active devices. An example of these are smart cards where information about a card holder or a card holder's accounts or finances may be stored. To inexpensively manufacture rechargeable active devices such as these, it is desirable to reduce the size of the energy storage components and use less expensive components that may have relatively low storage capacity. Additionally, it is desirable to extend the life of rechargeable active devices by providing smaller energy storage components and eliminating physical contact mechanisms ordinarily used in battery charging systems.